Energy and Work
Factorio simulates many aspects of real physics and the quite correct use of energy is one important aspect.
Energy and work are directly dependent.
Game physics is not reality
Another explanation can be found in the Forum
Work is "stored energy" or the "result of using power". If you divide the work into parts and release the parts in some time you have energy.
Work is measured in Joules, which is one Watt over the time of one second. See Units#Work.
Types of work
Work is available (or storable) as
- Capacity in the Basic accumulators.
- Hot liquids. You can create them in the Boiler and store serious amount in the Storage Tank.
Energy / Power
Energy is the "ability to do work". The speed of this doing needs more or less power. The faster something works, the more power is needed, but the result (the work) is the same. In Factorio this is also used a lot to calculate, how much time is needed to produce stuff.
Types of energy
Fuel-based (Boiler, Burner)
There are some devices, which can use fuel directly.
That's the single parts! The whole process is also explained as Power Production.
Electricity is the only way to transport energy over long distances. Electricity itself doesn't pollute, the pollution comes either from burning fuel or consuming electricity.